within.ffdf: Evaluate an expression in a ffdf data environment

In ffbase: Basic Statistical Functions for Package 'ff'

Description

Same functionality as within. Please note that you should write your expression as if it is a normal data.frame. The resulting data.frame however will be a new ffdf data.frame.

Usage

## S3 method for class 'ffdf'
within(data, expr, ...)

Arguments

data	ffdf data object used as an environment for evaluation.
expr	expression to evaluate.
...	arguments to be passed to chunk.

Value

a modified clone of data.

Examples

ffdat <- as.ffdf(data.frame(x=1:10, y=10:1))
# add z to the ffdat
within(ffdat, {z <- x+y})

ffbase documentation built on Feb. 27, 2021, 5:06 p.m.